I love hot sauce, but I'm pretty picky* and Sriracha** has never done it for me. Luckily, I've found my alternative.
Sambal oelek is made by the same company, but it's pure, thick chili paste. The heat level is fairly intense, so consider yourself warned. You can find it at Asian food stores, and in other random places - I actually picked mine up at Smart and Final, of all places. Equally good as a dipping sauce for summer rolls or kefta kebobs. Also makes an excellent addition to cooked dishes that need a bit of heat.
*I won't touch Tabasco with a 10 foot pole, but I have an undying love affair with Tapatio sauce.
**It's probably blasphemy to even admit this while living in Los Angeles. Sriracha (aka rooster sauce) is practically a religion, especially because it's made nearby (excellent NYTimes article about the family run business here). Even if you aren't from LA, you've probably seen it touted all over various food shows. Top Chef contestants are almost universally obsessed with it.